/*响应式布局 电脑平板*/
@media screen and (min-width: 1024px){
    .download_app_back_img{
        position: fixed;
        z-index: -10;
        top: 0;
        width:100%;
    }
}

/*响应式布局 手机*/
@media screen and (max-width: 1024px){
    .download_app_back_img{
        position: fixed;z-index: -10; top: 0; height:100%;
    }
}